Conventional golf balls can be divided into two general classes: solid and wound. Solid golf balls include one-piece, two-piece (i.e., single layer core and single layer cover), and multi-layer (i.e., solid core of one or more layers and/or a cover of one or more layers) golf balls. Wound golf balls typically include a solid, hollow, or fluid-filled center, surrounded by a tensioned elastomeric material, and a cover.
Examples of golf ball materials span from rubber materials, such as balata, styrene butadiene, polybutadiene, or polyisoprene, to thermoplastic or thermoset resins such as ionomers, polyolefins, polyamides, polyesters, polyurethanes, polyureas and/or polyurethane/polyurea hybrids, and blends thereof. Typically, outer layers are formed about the spherical outer surface of an innermost golf ball layer via compression molding, casting, or injection molding.
Golfers often enjoy honing their skills by practicing on driving ranges, which generally have limited space and often involve hitting a ball into a water body. Golf ball manufacturers therefore seek to develop golf balls that can fly shorter distances at a given swing speed without meanwhile sacrificing the trajectory look of a regular distance golf ball so that a player can predict from shorter practice shots how well the player would likely have done using the regular distance golf ball on the golf course.
In this regard, U.S. Pat. No. 7,938,745 of Sullivan et al. (“'745 patent”) and its related applications/patents disclose low coefficient of restitution (CoR) golf balls having a maximum CoR of less than about 0.790 and a reduced flight distance while maintaining the trajectory look of normal flight distance golf balls such as the ProV1 having a higher CoR of 0.807 identified in Tables 8C and 8D of the '745 patent. Unfortunately, golf ball manufacturers have not been able to produce higher CoR golf balls having shorter flight distance and the flight trajectory look of regular distance high CoR golf balls. A need therefore still remains for high CoR golf balls having reduced flight distance and creating a flight path that looks like the perceived flight trajectory of regular distance high CoR golf balls. Such golf balls could provide meaningful practice feedback to those golfers using regular high CoR golf balls on the course, and would be particularly desirable if meanwhile producible cost effectively within existing golf ball manufacturing processes. The current golf balls of the invention and methods of making same address and solve these needs.